5-Acetylsalicylamide for defect passivation & crystallization regulation in inverted perovskite solar cells

We introduce 5-acetylsalicylamide (5-ASA), a pharmaceutical intermediate, as an additive in FA_0.95Cs_0.05PbI₃ perovskite ink. Machine learning (ML) screening and density functional theory (DFT) calculations reveal it simultaneously passivates undercoordinated Pb²⁺ and iodide vacancies defects, while modulating crystallization. The resulting films exhibit large grains, higher crystallinity, and lower defect density, leading to an enhanced power conversion efficiency (PCE) of 22.12% in inverted devices.